Process of catalytic cracking of petroleum hydrocarbons



Patented July 8, 1947 PROCESS OF CATALYTIC CRACKING OF PETROLEUM HYDROCARBONS Per Henning Wilhelm Agren, Nynashamn, Sweden, assignor to A. Johnson & 00., New York, N. I[., a company oi Delaware No-Drawing. Application June 24, 1944, Serial No. 542,005. In Sweden August 24, 1942 2 Claims. (Cl 196-52) The present invention relates to a process of catalytic cracking of petroleum hydrocarbons which is characterized by the fact that the hydrocarbons in the liquid and/or vapor phase, in connection with cracking, are brought in contact with a catalyst entirely or at least partly consisting of oil-shape and/or mineral residue of such shale, e. g. residue from distillation or burning thereof, such as shale ashes and the like.

The catalysts hitherto employed in the cracking of petroleum, consisting of metals, oxidic substances and the like, are either too sensitive to so called catalytic poisons, particularly sulfur which frequently occurs in petroleum, or else possess too little catalytic power to be suitable for industrial use without complicated arrangements. It has now been found that catalysts of oil-shale or similar material of the above stated kind, possess valuable properties in these respects. The catalyst may from the outset consist of ordinary shale ashes, i. e. ashes obtained in burning or calcining of oil-shale, with or without admixture of other suitable catalytic substances of low sensitivity to sulfur, or the 'catalyst may originally be wholly or partly composed of natural shale. This alsomakes it possible to carry out the catalytic treatment of petroleum hydrocarbons in contact with naturally occurring oil-shale or its more or less transformed residues, e. g. by pumping crude petroleum into drill holes in oilshale rocks simultaneously with or after a distilling off of the shale oil from the rock by the so called in situ-method, while heating the said drill holes and conveying the oil so that suitable operating conditions are produced. After a short period of operation the oil shale is, of course, free from its naturally occurring oil.

Suitable operating temperatures and pressures, both when treating the petroleum by contacting it in the drill holes with the catalyst forming part of the surrounding rock, and when carrying out the treatment in known petroleum cracking units,

are from 250 to 600 C. and from atmosphericpressure up to 50 atmospheres, under which conditions the catalysts in question have proven to function extremely satisfactory both in regard to yield and to durability. In order to obtain high yields it is suitable to let such gases as are contained in the reaction-mixture, particularly the low-molecular ones, pass over the catalyst several times.

I claim:

1. In the cracking of petroleum oils, the process which comprises passing such an oil into a hole drilled in a natural oil-shale rock formation in contact with said rock and while heating the drill hole to cracking temperatures, passing the oil into said hole until the natural oil content of the formation is exhusted and withdrawing the resulting products from said hole, thereafter continuing to pass oil into said hole and cracking it therein utilizing the catalytic properties of the natural rock formation to enhance the cracking of said petroleum oil, and withdrawing the cracked products from said hole.

2. In the cracking of petroleum oils, the process which comprises pumping crude petroleum oil into a hole drilled in an oil-bearing shale rock formation in contact with said rock while heating the drill hole sufficiently to bring the formation to a temperature within the range of about 250 to600 C. and under a pressure within the range of from atmospheric to 50 atmospheres, withdrawing the resulting products including cracked gases from said hole, passing oil into said hole until the natural oil content of the formation is exhausted, thereafter continuing to pass oil into said hole maintained at said cracking temperature and pressure while utilizing the catalytic properties of the rock to enhance the cracking of said petroleum oil, withdrawing the cracked products including cracked gases from said hole, and recycling said cracked gases to said hole during the cracking process.

PER HENNING WILHELM AGREN.

REFERENCES strap The following references are of record in the file of this patent:

UNITED s'rs'ras PA'I'ENTS Number Name Date 1,458,983 Kirby June 19, 1923 1,475,901 Thompson Nov. 27, 1923 1,707,759 Hampton Apr. 2, 1929 1,868,737 Eglofl July 26, 1932 2,054,725 Greenstreet Sept. 15, 1936 1,614,660 Darlington et al Jan. 18, 1937 2,078,945 Houdry May 4, 1937 1,342,741 Day June 8, 1920 2,265,923 Normand Dec. 9, 1941 1,940,725 Morrell Dec. 26, 1933 1,467,758 Day Sept. 11, 1923 1,917,324 Pier et a1 July 11, 1933 2,382,471 Frey Aug. 14, 1945 1,510,655 Clark Oct. 7, 1924 FOREIGN PATENTS Number Country Date 511,768 Great Britain Aug. 24, 1939 7 OTHER REFERENCES Dunstan et al., fThe Science of Petroleum, vol.

IV, pages 3085 and 3089. Published 1938 by 0xford University Press, New York. (Copy in Division 31.) 

